Primordial non-Gaussianities in new ekpyrotic cosmology

Shuntaro Mizuno*, Kazuya Koyama, Filippo Vernizzi, David Wands

*この研究の対応する著者

研究成果

6 被引用数 (Scopus)

抄録

We compute the non-Gaussianity of the curvature perturbation generated by ekpyrotic collapse with multiple fields. The transition from the multi-field scaling solution to a single-field dominated regime converts initial isocurvature field perturbations to an almost scale-invariant comoving curvature perturbation. In the specific model of two fields, φ1 and φ2, with exponential potentials, -Vt exp(-c tφi, we calculate the bispectrum of the resulting curvature perturbation. We find that the non-Gaussianity is dominated by non-linear evolution on super-Hubble scales and hence is of the local form. The non-linear parameter of the curvature perturbation is given by fNL = 5cj 2/12, where cj is the exponent of the potential for the field which becomes sub-dominant at late times.

本文言語English
ホスト出版物のタイトルAIP Conference Proceedings
ページ121-125
ページ数5
1040
DOI
出版ステータスPublished - 2008
外部発表はい
イベントKEK Cosmophysics Group Inaugural Conference - Accelerators in the Universe, AIU 2008 - Tsukuba
継続期間: 2008 3 122008 3 14

Other

OtherKEK Cosmophysics Group Inaugural Conference - Accelerators in the Universe, AIU 2008
CityTsukuba
Period08/3/1208/3/14

ASJC Scopus subject areas

  • 物理学および天文学(全般)

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